An array (hash) which contains pairs of language identifiers and translation hashes. Each translation hash maps a given lookup key (or phrase) into a corresponding text string for the given language. Thus, it is essentially a multi-lingual dictionary used for phrase translation. It is also used for handling user preference mappings. Thus, the 'e_row' value that one finds on the Site.Preferences page is loaded into $XLLangs during preference processing.